linux 内核操作串口

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <termios.h>

int main() {
    int serial_port = open("/dev/ttyS0", O_RDWR);
    if (serial_port < 0) {
        printf("Error %i from open: %s\n", errno, strerror(errno));
        return 1;
    }

    struct termios tty;
    if (tcgetattr(serial_port, &tty) != 0) {
        printf("Error %i from tcgetattr: %s\n", errno, strerror(errno));
        return 1;
    }

    cfsetispeed(&tty, B9600);
    cfsetospeed(&tty, B9600);

    tty.c_cflag |= (CLOCAL | CREAD);    /* ignore modem controls */
    tty.c_cflag &= ~PARENB;            /* clear parity bit */
    tty.c_cflag &= ~CSTOPB;            /* only need 1 stop bit */
    tty.c_cflag &= ~CSIZE;
    tty.c_cflag |= CS8;                 /* 8-bit characters */
    tty.c_cflag &= ~CRTSCTS;           /* no hardware flowcontrol */
    tty.c_iflag &= ~(IXON | IXOFF | IXANY); // shut off xon/xoff ctrl
    tty.c_lflag &= ~(ICANON | ECHO | ECHOE | ISIG); // make raw
    tty.c_oflag &= ~OPOST;              // make raw

    if (tcsetattr(serial_port, TCSANOW, &tty) != 0) {
        printf("Error %i from tcsetattr: %s\n", errno, strerror(errno));
        return 1;
    }

    char read_buf [256];
    while (1) {
        int n = read(serial_port, &read_buf, sizeof(read_buf));
        if (n < 0) {
            printf("Error reading: %s", strerror(errno));
            break;
        }
        printf("%.*s", n, read_buf);
    }

    close(serial_port);
    return 0;
}